Thanks. I was able to put the code in but did not help much. For example, I uploaded a file called Test.xls on my Wiki: http://wiki.koolsolutions.com/index.php?title=File:TestFile.xls
But when I click on the link "Edit this file using an external application", all I get is a Firefox Download box (I am using Windows Machine) for index.php instead. How I can edit this excel file in place using MS Excel which is installed on my system.